11
Fan Powered Terminal Units IOM
FIGURE 6 – Typical Perimeter Installation – Constant Volume Fan-Powered Box
DISTRIBUTION DUCT
LINED DISCHARGE DUCT
CONSTANT VOLUME FAN BOX W/
ELECTRIC HEAT
PRIMARY AIR
INLET
ROOM
SENSOR
CONTROL
ENCLOSURE
PTBS LINEAR BOOT DIFFUSER
3.
Fan boxes should not be attached to octopus sections
immediately downstream of the unit.
4.
Install optional return-air filters before operating the
unit.
5. Where construction filters were supplied with the box,
leave filters in place until installation is complete and
building is cleaned for occupancy.
STEP 3 - POWER WIRING
(see Figure 7.)
1. All power wiring must comply with local codes and with
the NEC (National Electrical Code) ANSI/NFPA (American
National Standards Institute/National Fire Protection
Association) 70-1981. Disconnect switches are optional
equipment. Electrical, control and piping diagrams are
shown on the exterior labeling or on a diagram inside
the control and high-voltage enclosure covers, unless
otherwise specified in the order write-up. All units are
wired for a single point electrical connection to the
fan and electric heater (if equipped). Electric heaters
provided by Krueger are balanced by kW per stage. The
installing electrician should rotate incoming electric
service by phase to help balance overall building load.
2.
All field wiring must be provided with a safety disconnect
per NEC 424-19, 20, and 21.
3.
Disconnect all incoming power before wiring or servicing
STEP 2 - MAKE DUCT CONNECTIONS
1. Install supply ductwork on each of the unit inlet collars.
It is recommended that 3 duct diameters of straight duct
are supplied to the inlet of the unit. An elbow put at the
inlet of the unit will create turbulence at the inlet making
it difficult for the flow sensor to accurately measure
the airflow. Check that the pressure pick-up in primary
air collar is located properly and that air supply duct
connections are airtight. Install supply ductwork on unit
inlet collar, following all accepted medium-pressure duct
installation procedures. Seal joints against leakage.
NOTE: For maximum efficiency in controlling radiated
noise in critical applications, inlet ducts should be
fabricated of 24-gauge minimum sheet metal in place
of flex connections. Flex duct is extremely transparent
to radiated sound; consequently high inlet static’s (Ps)
or sharp bends with excessive pressure drop can cause
a radiated noise problem in the space. If flex duct is
used, it should be limited to the connection between
the distribution duct and the boot diffuser.
2. Install the discharge duct. On units with electric heat, the
recommended minimum distance of straight duct before
any transitions, elbows or branch connections is 48”. It is
strongly recommended that lined discharge duct be used
downstream of the unit. Insulate duct as required.
Summary of Contents for KLPP
Page 49: ......